I played CTP 1 & 2. The 1 was interesting, but very "unbalanced" by many aspects. Early in the game, I remember I lost 27 units of roman legionaries (!!) against a single spearman unit that was barricaded atop a mountain. The late part of the game was interesting, but underexploited and messy IMHO. Building underwater, in space, that was a little too much, and at this point the AI wasn't following anyway.
Vanilla CTP2 was plagued, amongst other things, by a failing AI, especially in war. Apolyton made great job.
My dream in the genre would be a crossing between Civilization and Imperium Galactica, where you could build colonies on the Moon, other planets, etc...